these foods are so fiber rich and the exact opposite of calorie dense I don't think you really have to worry about it. I would not go crazy on meat and dairy especially at first. but as long as you are heavy on the vegetables at dinner a 6-8 ounce piece of chicken isn't going to mess you up. and you will be full on cooked broccoli or sweet potatoes long before you max out on calories. I had heaping plates of sweet potatoes and green beans and I was just too full to keep going and then I had my resistant starches for the next day.
If I was going to do this diet again for weight loss, I would first focus on eliminating the bad stuff and only eating the good stuff. I would not limit portions at all. I would go all in on it and eat as much as you want - BUT I would make for damn sure you were at zero added sugars and no animal saturated fat. Don't cheat with that honey peanut butter at HEB, don't put a smidge of butter in your oatmeal, don't pinch some brown sugar in there. don't. do it.
4 weeks in of no added sugar and no animal fat, then take a look and see what's going on. In theory you could be eating too much but again once your body is off the shit, it has a lot of room for good carbs and a lot of room for good fat.
If I recall correctly I also added yogurt later, I definitely added milk later, so limited dairy for sure at the beginning.
on meat - I'd not go past one chicken breast for dinner, or on pork tenderloin I would have 5 or 6 slices. Fish an HEB filet even if 1.5 servings is fine. I would not eat those meat servings twice a day.
whole grains does not mean whole grain pasta or whole grain bread, I mean oatmeal, museli stuff like that.
strict is the key.
a month in you might find like I did that I actually craved certain healthy foods. my go to's were roasted okra, watermelon, grapes and potatoes. god I would just devour potatoes.